1. Field of the Invention
This invention relates to an apparatus for supplying fluid to an ink jet nozzle. In particular, this invention relates to a tall, narrow, rectangular cartridge formed with a recess in the inner base so as to eliminate residual ink left therein.
2. Description of Prior Art
xe2x80x9cInk-jet printer with user replaceable printing system cartridgexe2x80x9d, disclosed in U.S. Pat. No. 4,831,389, provides a rigid ink container supplying ink to the nozzle. Owing to the geometrical structure of the ink container, the ink cannot be entirely transmitted to the nozzle. thus, a volume of the ink is left as residue. Erickson et al discloses a trapezoidal ink container to eliminate the residual ink left therein. However, it is not easy to remove the trapezoidal container from the printer. Although a flat ridge cartridge with lunate structure, disclosed in xe2x80x9cInk jet printer incorporating high volume reservoirsxe2x80x9d, U.S. Pat. No. 5,686,947, can eliminate the residual ink, the replacement of the cartridge is inconvenient and the user cannot determine the actual volume of ink left in the cartridge at a given moment. xe2x80x9cContinuous Refill of spring bag reservoir in an ink jet swath printer/plotterxe2x80x9d disclosed in U.S. Pat. No. 5,745,137 and xe2x80x9cNegative pressure ink delivery systemxe2x80x9d disclosed in U.S. Pat. No. 5,757,406, respectively provide a flat and flexible ink bag to store the ink. However, the user also cannot tell the actual volume of ink left in the flexible bag from the outside.
To solve the above problem, the primary object of this invention is to provide a cartridge for supplying ink to a jet nozzle and leaving minimum residual ink therein. The present invention comprises a reservoir with a tall, narrow, rectangular structure for storing the ink and a transmitting device having a duct disposed in the reservoir so as to transmit the ink to the ink jet. A transparent panel disposed on the reservoir is used to indicate the volume of the ink left therein. The tall-narrow rectangular reservoir has an inner base that is composed of a primary surface and a secondary surface. In comparison with the level ink, the secondary surface is lower than the primary surface. Therefore, the residual ink left on the primary surface can be gathered and guided to the secondary surface.
The present invention is characterized in that a recess (rectangular, trapezoidal, triangular, or a semi-spherical) with a secondary surface is formed next to the primary surface, and the opening of the duct is disposed in the recess. The residual ink left on the primary surface can therefore be finally gathered and guided into the recess.